Intermittent missing disk drive

[rew45]

I have just installed Windows 7 Home Premium on an HP Pavillion a1629.uk, and the second internal drive is sometimes not present on booting up. The failure rate is about one time in ten. Originally the machine had C: and D: drives with XP installed on C:. The original C: drive was discarded, and a clean installation of Windows 7 was made on on a new 500 GB disk. The original D: 500 GB drive (Seagate ST3500320AS) was left in place, but as stated is sometimes not detected. The drive is always present in the BIOS, before windows boots. On the occasions that it is not detected in Win7, checking for hardware changes in Device Mangler does not help. Any suggestions, please?

 

[Ztruker]

Are the driver IDE (PATA) or SATA? If IDE, how are they jumpered and are they connected with a 40 wire or 80 wire cable? If 80 wire then then they may work if jumpered for CS (Cable Select) but make the one connected to the end of the IDE cable Master and the other Slave should always work.

 

[rew45]

Both drives are SATA, but thanks for the suggestion.
Richard